Art of spring manufacture



Filed May 26, 1938 SYLVAN J. BECKER Patented Mar. 25, 1941 ART OF SPRING MANUFACTURE.

Sylvan J. Becker, Lake Bluif, 111., assignor to The Associated Spring Corporation, Bristol, Conn,

a corporation of Delaware Application May 26, 1938, Serial No. 210,287

1 Claim.

This invention relates to the art of spring making and, more particularly, is intended to provide a new and improved method which is to be followed in tempering a spring and giving 5 an initial set thereto.

In the manufacture of springs, as heretofore performed, it has been the usual practice to first deform the material, such as wire or metal plate, to the normal, unstressed position which the spring will occupy when not loaded, and to then set the spring in this position by heat or other suitable treatment. While in this unstressed condition the prior art practice has been to temper the spring by heat treatment or otherwise. It will be seen that when a spring formed according to this prior art practice is deformed from its unloaded position, as by loading, the fibres of the spring material will be moved away from the position which they occupied when the spring was given its temper.

In accordance with the present invention, this prior art practice is not followed. In applying my invention to the manufacture of springs I finish the material to spring temper, as by heat treatment, while the spring is in a condition or position which it will occupy when loaded, that is, a condition or position which is within the working range of the spring. After the heat treatment is completed I deform the spring to its normal condition or position, that is, the condition or position which the spring will occupy or assume when it is unloaded. The spring is set while in this position in order to give it this normal unloaded shape.

It will be seen that by giving the spring its temper while it is in a position which is within the range of positions it will occupy when loaded, i. e. its working range, the internal structure of the steel composing the spring will be fixed in the position which it will occupy when the spring is worked in use. It is true that the subsequent deforming and setting operations will cause the spring to lose much of the characteristics of its original state as tempered, but any effect of the original heat treatment which remains after the deforming and hardening operations will be in favor of the spring. Expressed otherwise, it may be said that when a spring formed according to this invention is worked from its unloaded or 0 normal position to a deformed position the fibres of the spring material will tend to return to the position in which they were originally fixed by the tempering treatment. Thus, their deformation will have less tendency to cause fracture or fatigue of the spring, and I have found that the life of the spring will be greatly increased if formed in the manner described.

In the drawing forming part of this application there are illustrated the steps in the formation of a Belleville clutch spring according to the invention. In the drawing,

Fig. 1 is a plan view of the spring; Fig. 2 is a sectional view, taken on the line 2-2 of Fig. 1, showing the position or condition of the spring during tempering, and

Fig. 3 is a View, similar to Fig. 2, showing the position or condition of the spring after deformation from the position or condition of Fig. 2 to its unstressed position.

An. example of the practical application of my invention, its use in the manufacture of coned Belleville springs may be considered.

Such

ed, are deformed toward a flat shape.

In the manufacture of such springsaccording to my invention, the spring is formed from fiat metal plate and this plate is given spring temper, as by heat treatment, while in the flat condition shown in Fig. 2 of the drawing which, it will be observed, is within the working range of the Belleville spring. After the tempering operation the plate is deformed to the frusto-conical shape shown in Fig. 3 of the drawing and is set in that condition by proper heat treatment. will be seen that as the spring is worked or deformed from its normal frusto-conical shape to or toward a fiat condition the fibres of the spring will tend to return to the position or condition which they were given by the tempering operation.

While I have particularly described my invention with respect to only one specific type of spring, it will be apparent that the invention is not in any way limited to use in the manufacture of that particular type of spring but may be applied generally to spring making. No limitation on the scope of the invention is therefore to be implied from the foregoing description and reference must be had to the appended claim for a definition of the limits of the invention.

I claim:

The art of manufacture of coned Belleville springs which consists in treating fiat metal plate to give it a spring temper, deforming the plate to coned shape to provide ,a, coned spring, and setting the spring in such coned shape by suitable treatment.

SYLVAN J. BECKER. 

